Related Experiment Video
Updated: Jun 15, 2026

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
Incidence of aneurysmal subarachnoid hemorrhage in Norway, 1999-2007
H M Lindekleiv1, I Njølstad, T Ingebrigtsen
1Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
Objective:
To investigate changes and regional variations in annual incidence rates of aneurysmal subarachnoid hemorrhage (SAH) in Norway between 1999 and 2007.
Methods:
The authors retrospectively reviewed data from the Norwegian Patient Register for the period 1999-2007.
Results:
Crude incidence of aneurysmal SAH was 10.0/100,000 person years [95% CI (confidence interval): 9.7-10.3] and was higher in women (12.0/100,000 person years; 95% CI: 11.5-12.5) than men (8.1/100,000 person years; 95% CI: 7.7-8.4). Decreasing annual incidence rates were observed from 11.1/100,000 person years (95% CI: 10.5-11.6) in the period 1999-2001 to 8.9/100,000 person years (95% CI: 8.4-9.4) in the period 2005-2007 (P for trend <0.001). Regional variations were observed, from 8.4/100,000 person years (95% CI: 7.7-9.00) in the southern region, 10.4/100,000 person years (95% CI: 9.5-11.2) in the central region and 11.9/100,000 person years (95% CI: 10.8-12.9) in the northern region.
Conclusions:
Incidence of aneurysmal SAH in Norway decreased from 1999 to 2007, with significant regional variations indicating an increasing gradient from south to north.
Related Concept Videos
Hemorrhagic Stroke l: Introduction
Aneurysm II: Clinical Manifestations and Diagnostic Studies
Hemorrhagic Stroke ll: Pathophysiology
Aneurysm III: Interprofessional Care
Aneurysm I: Introduction
